​​Friction and pressure combine to create shear forces that stretch and irritate connective tissue within the epidermis initially creating a “hot spot.” Later, as the epidermis tears and plasma leaks into the torn tissue, a blister will form. As long as shear forces are present, the skin continues to delaminate and the blister grows until it breaks. More pressure—due to a heavy pack or persistent hiking downhill—will cause deeper damage and a more painful blister. Both the prevention & treatment of friction blisters require adding an external “sliding layer” to prevent shear forces from building within the skin.

​Friction Blister Prevention

• Wash skin, socks, etc. on a regular basis. Wear gaiters over boot tops and laces to keep dust & dirt out. Keep skin, socks, gloves, etc. dry. Change socks regularly. Sleep in clean, dry socks. An antiperspirant may help keep feet dry.
• Increase pack weight and distance slowly to allow the skin to adapt to new forces. Avoid continuous downhill hiking until skin has had time to strengthen.
• Make sure footwear, gloves, and clothing fit well.
• Anticipate blisters; treat hot spots immediately BEFORE they become blisters by adding an external sliding layer to reduce shear forces within the skin. Use tincture of benzoin and flexible medical tape to create a sliding layer between the skin and the inner sock. Add a friction patch (ENGO®) to footwear to create a sliding layer between the outer sock and footwear. [The use of Duct Tape® or Gorilla Tape® is not recommended to prevent or treat hot spots: the glue is very strong and often increases friction within the skin layers rather than reducing it.]

Pathophysiology
While posterior hip dislocations are somewhat common in head-on motor vehicle accidents and occasionally occur in elderly people with prosthetic hip joints during a minor slip or fall, they are quite rare in a wilderness environment. Most posterior hip dislocations require a significant traumatic MOI and many patients die from internal injuries to the pelvis, abdomen, chest, and head. Greater than 50% of patients have long-term disability after reduction. The femoral head is highly vascular and may die if not quickly reduced. Posterior hip dislocations are increasing along with the popularity of extreme sports; one study indicated that snowboarders were more likely to suffer a posterior hip dislocation than skiers.

The hip joint is a ball-and-socket synovial joint: the ball is the femoral head, and the socket is the acetabulum. The adult hip is quite stable. As such, knee and lower leg injuries are often seen in conjunction with posterior hip dislocations. Due to the potential for significant complications, an attempt should be made to reduce posterior hip dislocations in the field.

Posterior Hip Dislocation Signs & Symptoms

• Patient presents on back or side with hip slightly flexed and the leg on the affected side shorter and rotated inward.
• Moderate to severe pain; associated nerve injury and loss of nerve function is possible.
• Patient may have fractures to the knee, patella, femoral head, neck, shaft, or socket (acetabulum).

Posterior Hip Dislocation Treatment

• If the leg on the side of the dislocation has no significant fracture, one rescuer stabilizes patient’s hips while the second squats with arms crossed under patient’s knee and lifts, using their legs, until femoral head relocates.
• If reduction is successful, there is no nerve damage, and no indication of internal injuries, begin a Level 3 Evacuation.
• Begin a Level 2 Evacuation for patients with an unreduced posterior hip dislocation; death of the femoral head and permanent nerve damage may occur anytime within the following 24 hrs without reduction.
  

Rib Fractures
In most cases, a simple, isolated rib fracture elicits sharp, knife-like pain, and respiratory distress; however, as the patient relaxes and begins to breathe with their diaphragm, the respiratory distress subsides. Depending on the location of the fracture and it's severity, if there are multiple rib fractures especially to the same rib or ribs (flail chest), the patient may present with or develop respiratory distress due to lung damage and/or internal bleeding.

Isolated Rib Fracture S/Sx

• Sharp knife-like pain on inspiration that resolves with abdominal breathing.
• Lung damage and/or internal bleeding are possible.

Isolated Rib Fracture Treatment

• Position patient in position of comfort. Reassure & coach abdominal breathing.
• Begin a Level 3 EVAC. Depending on pain, patients may be able to self-evac; minimize patient’s work load (no/light pack). Do not bind patient’s ribs; instead, encourage them to take a deep breath every 20 minutes; both help prevent a secondary pneumonia.
• Begin an urgent, level 1 evacuation if lung damage and/or volume shock is suspected.

Multiple Rib Fractures S/Sx

• Sharp knife-like pain on inspiration that is usually not relieved by abdominal breathing; lung damage and/or internal bleeding are likely.

Multiple Rib Fractures Treatment

• Position patient in position of comfort: sitting if awake; lying on injured side if voice-responsive, pain-responsive, or unresponsive.
• Reassure & coach patient to abdominal breathe. Do not bind the patient’s ribs; instead, encourage them to take a deep breath every 20 minutes; both help prevent a secondary pneumonia.
• Begin an urgent, level 1 evacuation if lung damage and/or volume shock is suspected.

• Air may become trapped in the soft tissue surrounding the eye (orbital emphysema) as a result of the traumatic event and often presents after sneezing.

Orbital Fracture Treatment

• Treat for concussion, ICP, and cervical spine injury as necessary. If none are present & vision is intact, begin a Level 3 EVAC. Surgery may be required.
• If vision is impaired, begin a Level 2 EVAC. Surgery is usually required.

Zygomatic (cheek) Fractures
Zygomatic Fracture S/Sx

• ± local swelling, bruising, and/or deformity.
• ± decreased sensation to the skin of the upper cheek, lateral nose, upper lip, & gums.
• ± concurrent orbital or maxillary fractures.

Zygomatic Fracture Treatment

• Treat for concussion, ICP, and cervical spine injury as necessary. If none are present, begin a Level 3 EVAC. Surgery may be required.

Nasal Fractures 
Nasal Fracture S/Sx

•  ± local pain, tenderness, swelling, crepitus, bleeding, deformity, bruising of nose or under eyes (black eye), lacerations, & difficulty breathing through nose; mouth breathing is common.
• The nose can visually appear straight but the septum can be internally deviated.

 Nasal Fracture Treatment

• Treat for concussion, ICP, and cervical spine injury as necessary. If none are present, consider a Level 3 EVAC. Reduction/repair is done within 72 hrs, 5-10 days after swelling has gone down, or repaired surgically after the initial damage has healed.
• Begin a Level 3 EVAC if pain or swelling remain after three days, the patient develops a fever, nasal breathing remains restricted after swelling goes down, or the patient’s nose is crooked.
• Treat for bloody nose (epistaxis) as necessary.
• Begin a Level 2 EVAC if CFS appears to be present: runny nose, salty postnasal discharge, or positive ring sign. If CFS is present in the pt’s blood, it will separate if the patient’s blood is placed on porous paper or cloth (coffee filter, gauze, etc.).

Maxillary (mid face) Fracture
Maxillary Fracture S/Sx

• ± local pain, tenderness, swelling, bruising, crepitus, bleeding, deformity, broken teeth, & difficulty breathing through nose or mouth.
• Patient’s bite may be affected.
• ± concurrent orbital, nasal, or zygomatic fracture.

Maxillary Fracture Treatment

• Clear airway and separately treat fractured or avulsed teeth.
• Treat for concussion, ICP, cervical spine injury, obstructed airway, and any concurrent orbital, nasal, or
• zygomatic Fx as necessary. If none are present, begin a Level 3 EVAC.
• Begin a Level 2 EVAC if obvious deformity is present; surgery is required.

Mandibular (jaw) Fracture
Mandibular Fracture S/Sx

• ± local pain, tenderness, swelling, bruising, crepitus, bleeding, deformity, broken teeth, asymmetrical bite, no ROM, & difficulty breathing through mouth.
• Ask the patient to bite down on a credit card or similar item between the teeth on each side of the patient’s jaw. The patient should be able to hold on to the card against mild resistance.

Mandibular Fracture Treatment

• Clear airway and separately treat fractured or avulsed teeth.Treat for concussion, ICP, cervical spine injury, and obstructed airway as necessary. If none are present, begin a Level 3 EVAC.
• Begin a Level 2 EVAC if obvious deformity is present, the patient is unable to hold a thin item between their teeth against resistance, or there is no range of motion in their jaw; surgery is required.

Drowning & Traumatic Injuries   
While the majority of SUP drowning victims were novices not wearing a life-jacket, at least one drowning victim has died on a river when her leash snagged on hidden debris. Death from head injuries is also a concern when examining surf related accidents. And finally, mild traumatic knee and elbow injuries have occurred in whitewater paddlers. Interestingly, much of the protection available is controversial: The pros and cons of wearing, a leash, helmet, or knee & elbow pads are discussed below.

To Wear or Not to Wear...a Leash
Purchasing and wearing a leash with your paddle board should NOT be a forgone conclusion but it should be a serious consideration. Your board floats. If you don't wear a life-jacket, you will want to keep your board handy. A leash in flat, calm, protected water, especially for novices, may not be necessary and may well impede learning. On the other hand, wearing a leash while touring, in waves, or surf is usually a pretty good idea and will save you a long swim, or worse, should you fall off your board in heavy surf, strong current, or high wind. Wearing a leash in whitewater is a bit controversial. If you spend a lot of time surfing or running high volume rivers, consider a leash. If you run creeks and small rivers with debris and/or mid-river rocks, you probably shouldn't wear one as it increases your chances of entrapment. If you do choose to wear a leash in whitewater, you'll want one that clips to your life-jacket or waist (not your ankle or knee as these are difficult to reach in strong current), has quick release and break-away functions, and practice using it in strong current. If you choose to wear a leash in flat-water or surf and don't typically wear a life-jacket, you'll likely want one that attaches to your ankle or knee.

To Wear or Not to Wear...a Life-jacket
While wearing a life-jacket definitely increases your safety, they are somewhat constraining, are hot in the summer, interfere with tan-lines, and are therefore, controversial. Your choice to wear one (or not) depends on your paddling background and your risk assessment: Surfers tend to shun life-jackets and rely on their swimming ability and their board's floatation for protection; whitewater paddlers tend to bring and put on a life-jacket out of force of habit; and novices tend to wear what their instructor or friends wear. Manufacturers try to address comfort via design; inflatable life-jackets stored in belt-packs and activated by a pull-tab are available. No life-jacket will maintain an unresponsive person face up in rough water. NOTE: Many states consider paddle boards a water craft and require operators to either wear a life-jacket or have one on board; some states require board to have lights if used after dark.

To Wear or Not to Wear...a Helmet
Over the years, people have started to wear helmets in lots of sports where they didn't used to: biking, skate boarding, and skiing to name a few...so why not with an SUP? There have been head injuries and deaths in the surfing community (primarily from hitting their board) yet most surfers shun helmets in the same way they do life-jackets. This trend carries over to SUPs. Conversely whitewater paddlers have grown accustomed to wearing a helmet; after all, if you paddle a kayak or C-1, you are essentially tied into your boat with thigh braces and a spray skirt, and being upside down with rocks coming at your head seems to suggest, even to the most brain dead, that a helmet is a good idea. Again, this trend carries over to SUPs. Flat water canoeists and kayakers typically don't wear helmets (not much momentum if you aren't be pushed around by the water) and, once again, this trend carries over to SUPs. Should you wear a helmet? The answer is easy if you've had a previous head injury and are paddling in surf or whitewater: Wear one. Period. For everyone else, it's controversial. You need to make a personal risk assessment and then a decision. Base both on the likelihood of falling and hitting your head (on the board or something else). The bottom line is that it's safer to paddle with a helmet in the surf and whitewater, than not.

To Wear or Not to Wear...Body Armor
What? Wear body armor? Are you serious? Well, yes, on whitewater (or if you kneel on your board a lot). If you paddle on shallow rivers or tight rivers with lots of exposed rocks you should consider wearing knee and/or elbow pads. Also consider armored shorts with hip and sacral protection. Having your board stop suddenly after scraping the bottom on a rock tends to toss you forward onto the board or into rocks on the bottom of the river. Most paddlers land hard reasonably hard on their knees, elbows, hips, or back. All are somewhat fragile and hurt considerably when abruptly contacting a rock. Pads protect them.

Introduction
Stand up paddle boarding has taken off everywhere there's water: on flat-water, in the surf, and on whitewater. With it come a number of potential problems. Correctly touted as an excellent core workout, a discussion of effective training methods and possible injuries are often overlooked...until something starts to hurt. By then it's too late. Overuse injuries are common. While the overuse injuries in SUP are similar to other paddle sports, they are are exacerbated by the increased leverage of the paddle and the standing position. In order to propel the board forward force must be transmitted from the paddle through the paddler's entire body. Joints are the week points: wrists, elbows, shoulders, back, knees, and ankles. The exact process that makes stand up paddling so good for your core also makes it potentially bad for your joints. There are six things you need to consider when training/paddling SUPs:

1. Your paddle.
2. Your body.
3. Technique
4. Strength & flexibility training.  
5. The type of paddling you do. 
6. Doing too much too fast. 

Your Paddle
You can reduce the strain on your joints by decreasing the length of your paddle, choosing a more flexible paddle shaft, and choosing a small blade size. Decreasing the paddle length directly reduces the size of the lever and therefore the strain on your body. In addition, a shorter paddle lowers your top hand and directly reduces forces on your rotator cuff, shoulder tendons, and cervical spine compression. That said, you don't want a paddle that is too short either as this will cause you to bend over more and increase the strain on your lower back.

A flexible paddle shaft absorbs some of the explosive energy during the catch phase of a stroke and spreads the energy release throughout the stroke's length; this dramatically decreases the initial impact on your joints and the potential for damage. Alternatives to carbon-fiber (the stiffest) and fiber-glass blades (next in line) are wood and bamboo.

A smaller blade size reduces the surface area of the blade and the amount of energy required for each stroke. While you can purchase smaller blades commercially, you can also cut down the size of your current blade with a jig saw (remember to smooth/sand the edges if you work on your own paddle).
  
Your Body
Each individual is unique. Injuries, age, fitness, strength, and flexibility all play an important part in determining what kind of paddling you choose to do and how you approach doing it. For instance, if you have low back problems, it's a better choice to paddle on flat water than in strong whitewater or surf as the sudden movements required for either whitewater paddling or surfing will increase the likelihood of low back injury as you attempt to react to the required changes. Don't ignore your body's history or what it tells you as you paddle and after.

Technique
Learning the proper paddling technique and paddling on both sides of your board is vital to preventing overuse injuries. Your muscles are designed to be in balance and, in order to prevent injury, you need to keep it that way by learning to paddle correctly on both sides of your board. This may be more difficult that it sounds when surfing or paddling in whitewater as paddlers tend to favor one side or the other.

Strength & Flexibility Training
 If you want to paddle on a regular basis, you'll benefit by spending some time cross-training to avoid injuries. A quick web-search will reveal a number of SUP specific training regimes; one is sure to meet your needs.

The Type of Paddling You Do
Paddling SUPs on flat-water, in the surf, and on whitewater requires different equipment and skills. The forces on your body are different as well. This means that the types of injuries you can sustain are somewhat specific to the type of paddling you do. Flat-water paddling is typically limited to overuse injuries. While surf and whitewater paddlers are also susceptible to the same overuse injuries as flat-water paddling, moving water is strong and paddling in it increases the chances of muscle and tendon damage; furthermore, traumatic injuries and drowning are also possible.

A concussive injury, should it occur, can be functional or structural. A person with a functional concussive injury will present or develop S/Sx, typically within two hours; however, standard imaging techniques (CT, MRI) show no structural damage. The S/Sx of a functional injury—see the chart below—are likely caused by axional stretching and disruption of ion channels, follow a predefined progression, and usually resolve on their own within 7-10 days; although, in some cases, S/Sx may persist for months. That said, structural damage is possible and may lead to increased intracranial pressure (ICP) and potentially death in rare cases. The concern from a field perspective is whether a person with an apparent positive MOI can remain in the field or requires an evacuation. And, if an evacuation is necessary: What is its urgency?